Subsea flow boosting pumps are generally used to deliver production fluid from subsea wells to remote storage or processing facilities. Such pumps may be submersible pumps installed in the production well (e.g., electrical submersible pumps or ESPs) or pumps located external the production well (e.g., seabed booster pumps). U.S. Pat. No. 6,688,392 to Shaw, which is incorporated herein by reference, describes a system for flow pressure boosting of hydrocarbon fluids in a subsea environment. Shaw describes a hydrocarbon flow boosting system including: a producing well for producing hydrocarbon fluids, a cased dummy well hydraulically connected to the producing well for receiving hydrocarbon fluids, and a pump and motor disposed in a liner in the dummy well for taking suction flow from the dummy well and boosting the flow energy of the discharge flow of hydrocarbon fluids. Particularly, the flow boosting system of Shaw may be operated by flooding the annulus of the cased dummy well with hydrocarbon fluids and pumping the fluids upward out of the annulus via the liner to a subsea processing station (as shown in FIG. 1 of Shaw). The motor of the pump in Shaw is thus surrounded by hydrocarbon fluids and may not be accessible for cooling facilities.
Accordingly, there exists a need for a flow boosting pump system whereby the pump motor is isolated from the production fluid such that motor cooling facilities may be employed.